Search results for "Drain"
showing 10 items of 417 documents
Propagation of precipitation measurement biases into the hydraulic modelling of urban drainage systems: a case study
2021
Precipitation is the primary source of freshwater, while it can have great socio-economical impacts associated with extreme weather events such as floods and droughts. Good quality hydro-meteorological data is an essential condition not only for climate analysis but also for warning systems, hydraulic structures design, risk assessment, etc. In fact, precipitation is one of the most intensively used variables in hydrological modelling and its measurement accuracy is of foremost importance (Peterson et al., 1998). Accurate and timely knowledge of precipitation characteristics at urban and natural basins scales is essential for understanding how different catchment hydrological systems operat…
Uncertainty estimation of a complex water quality model: GLUE vs Bayesian approach applied with Box – Cox transformation
2010
In urban drainage modelling, uncertainty analysis is of undoubted necessity; however, several methodological aspects need to be clarified and deserve to be investigated in the future, especially in water quality modelling. The use of the Bayesian approach to uncertainty analysis has been stimulated by its rigorous theoretical framework and by the possibility of evaluating the impact of new knowledge on the modelling estimates. Nevertheless, the Bayesian approach relies on some restrictive hypotheses that are not present in less formal methods like GLUE. One crucial point in the application of Bayesian methods is the formulation of a likelihood function that is conditioned by the hypotheses …
Uncertainty propagation throughout an integrated water-quality model
2010
In integrated urban drainage water quality models, due to the fact that integrated approaches are basically a cascade of sub-models (simulating sewer system, wastewater treatment plant and receiving water body), uncertainty produced in one sub-model propagates to the following ones depending on the model structure, the estimation of parameters and the availability and uncertainty of measurements in the different parts of the system. Uncertainty basically propagates throughout a chain of models in which simulation output from upstream models is transferred to the downstream ones as input. The overall uncertainty can differ from the simple sum of uncertainties generated in each sub-model, dep…
Greenhouse gas emissions from integrated urban drainage systems: where do we stand?
2017
Integrated urban drainage systems (IUDS) (i.e., sewer systems, wastewater treatment plants and receiving water bodies) contribute to climate change being sources of greenhouse gas emissions (GHG). This paper, produced by the International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, reviews the state-of-the-art and the recently developed modelling tools used to understand and manage GHG emissions from IUDS. Further, open problems and research gaps are discussed, while proposing a framework for handling GHG from IUDS. The literature review reveals that there is a need to strengthen and partially adequate already available mathematical mo…
EVALUATION OF DIFFUSE AND CONCENTRATED POLLUTION AT WATERSHED SCALE
2009
The study presents an integrated approach in order to analyse and quantify pollution dynamics at basin scale depending on concentrated and diffuse sources. More specifically, an integrated model for urban drainage system has been exploited in order to simulate the complex sewer network - wastewater treatment plant and receiving water body. Moreover, a quali-quantitative model has been developped in order to simulate the non-point sources pollutant (agricultural and zoo-technical) in term of water river discharges and nutrient, produced from the wash off of soils. Finally, different models have been coupled in order to reconstruct the whole pollutant load for the receiving water body and to …
Parameter uncertainty analysis of water quality model for small river
2009
Pleural fluid collection and ultrasound guided percutaneous drainage
2010
Heterogeneous vertical structure of the bacterioplankton community in a non-stratified Antarctic lake
2013
10 páginas, 4 figuras, 2 tablas.
Rewards of reforms: Can economic freedom and reforms in developing countries reduce the brain drain?
2019
The objective of this paper is to investigate the impact of economic freedom on brain drain from developing countries to rich countries. Previous literature on brain drain has examined social, political and economic determinants. However, no study in the literature so far has studied this proposed relationship. We employ the Economic Freedom Index sourced from the Fraser Institute as a proxy for economic freedom and the rate of moderately skilled and highly skilled emigration functions as a proxy for brain drain. Our sample consists of 142 countries covering the period 1990–2010. We estimate the results using a two-way fixed effects regression estimator. The results show that an increase in…